The marine gobiid fish, Luciogobius platycephalus Shiogaki and Dotsu (1976) is ananguilliform in shape and grows to 80 mm in total length.Over three hundred and fifty specimens of the goby were collected from Kawahara and Nomo, both near Nagasaki City on the western coast of Kyushu (Fig.1).The habitats of the goby are restricted to the upper intertidal zone where pebbles and stones are sedimented over the hollows of the rocky bottom and the bottom is exposed to the air for several hours during the ebb tide (Fig.2, A).During the ebb tide the goby was found concealing itself among pebbles and stones.The goby fed on small crustaceans.From the examinations of the specimens collected through all seasons, it seems that the goby grows to about 50 mm long in a year and to about 70 mm in two years (Fig.3).
The spawning season at Kawahara seemed to extend from the beginning of October to the end of December.Seven egg masses were collected from the habitat on the coast of Kawahara on October 23, 1972.The eggs were attached in a dense one-layer mass on the underside of a stone lying among pebbles and guarded by a male parent.Number of the eggs in each egg mass ranged from 66 to 528.The eggs are club-shaped, from 2.05 to 2.28 mm in long axis and 0.68 to 0.75 mm in short axis, and provided with a bundle of adhesive filaments at the basal end (Fig.2, B, C).Hatching of the eggs, which were collected at 24 myomere stage, took place 129 hours after collection in an incubator with the temperature varing between 18.7 and 20.5°C (Fig.4).About four hundred hatched larvae, from 3.5 to 3.8 mm in total length, were kept in a 30-liter plastic vessel and fed on the rotifers, Brachionus plicatilis and nauplii of brine shrimp, Artemia sp.They were reared for 42 days after hatching and the biggest one grew to 16.2 mm long in the last planktonic life 35 days after hatching (Fig.5, A-G).A 22.2 mm long young was collected from the habitat on the coast of Kawahara to prove that the fish of this size already performs a benthonic life among pebbles as the adult fish does (Fig.5, H).
